Management of cardiovascular complications of BTKis: Are we complying with the good practice guidelines?

Bruton tyrosine kinase inhibitors (BTKis) were approved for use at the end of 2013 and have since been used for indications including chronic lymphocytic leukaemia (CLL), Waldenstrom's macroglobulinaemia and mantle cell lymphoma. The use of BTKis has increased significantly in the UK since they achieved NICE (National Institute for Health and Care Excellence) approval for frontline treatment of CLL in 2021. However, they are associated with significant adverse cardiovascular events. In September 2021 the British Journal of Haematology published good practice guidelines for the management of cardiovascular complications of BTKis. Our aim was to see whether these guidelines had been adhered to for patients taking BTKis. Method(s): Data was collected for all patients being prescribed BTKis (ibrutinib and acalabrutinib) in the South Tees NHS Trust in July 2022. Patients' medical records were used to assess whether their management adhered to the good practice guidelines. Data was collated for 67 patients in total. Result(s): The data showed that although all patients were consented for the risk of atrial fibrillation only 6% were consented for hypertension and only 1.5% for ventricular arrhythmias and sudden cardiac death. The guidelines recommend a baseline ECG (electrocardiogram) on commencement of treatment;however, only 7% had this completed and 0% had the minimum monitoring recommendation of 6-monthly ECGs. Thirty patients (45%) had an indication for a baseline echocardiogram;however, only one had this completed. For patients reporting symptoms of syncope, dizziness or palpitations only 50% had an ECG completed. Three patients developed worsening heart failure. The recommendations suggest referral to a cardio-oncologist;however, due to lack of availability of this service the referrals were instead made to the usual cardiologist. Conclusion(s): Although there was a lack of compliance with guideline recommendations, it should be considered that most usual checks were affected by COVID-19 outbreaks and a drop in face-to- face clinics, which were replaced by phone clinics and home delivery of medications. However, the premade consent forms for BTKis need to be updated to include consent for ventricular arrhythmias and sudden cardiac death. There also needs to be routine procedures in place to ensure that regular blood pressure testing and ECG monitoring occurs and that there is prompt recognition of cardiovascular complications. Action and implementation: To ensure improved compliance with these guidelines we plan to update our consent forms and create a proforma for clinic use to ensure that clinicians are aware of the various monitoring criteria required.

BTKi-treated CLL patients have Favourable survival outcomes but concerning levels of second malignancies and COVID-related mortality

Introduction: Bruton's tyrosine kinase inhibitors (BTKi) are used extensively within the NHS to treat specific B-cell malignancies with patients stopping BTKi usually due to adverse events or disease progression. The objective of this study was to analyse effectiveness of BTKi therapy for chronic lymphocytic leukaemia (CLL) at our centre compared to previously published real-world data from the UKCLL Forum (Follows et al, Blood 2019). In addition, we investigated treatment-related adverse events (AE) and second malignancies. Method(s): This is a single-centre retrospective study of 112 CLL patients treated with a BTKi for a minimum of 4 weeks between 2014 and 2022 (ibrutinib n = 71, acalabrutinib n = 38, zanubrutinib n = 3). Treatment was first line (n = 39), second line (n = 44) and 3+ line (n = 29). Patient demographics, duration of BTKi therapy, Aes, discontinuation reasons and second malignancies were collected. Aes were compared with a parallel cohort of 53 non-CLL BTKi-treated patients. Result(s): Median age starting treatment was 73 years, and 71% were male. Primary outcomes were discontinuation-free survival (DFS) and overall survival (OS). With a median follow-up of 3.90 years, the median DFS was 4.18 years (95% CI: 3.52-4.91) with a median OS of 6.35 years (95% CI: 5.52-NA). These compare favourably with previous UKCLL forum data (median DFS = 2.79 years;median OS = 4.66 years), although our patients were more likely to receive BTKi earlier in treatment (3rd line or beyond: 26% of our patients vs. 78% in the UKCLL Forum). The most common Aes included bleeding, cytopenia, infection, cardiac events and mouth ulcers, with 21% stopping BTKi for CLL due to Aes whilst 15% of non-CLL BTKi patients stopped due to an AE. Second malignancies were reported in 49% of CLL patients, yet only 34% of non-CLL patients. Among patients with a confirmed cause of death, infection was the most common cause (39%), followed by CLL (33%), then second malignancy (18%). Of the 31 deaths in 2020 and 2021, 7/31 (23%) were due to, or in association with COVID-19 infection. No COVID-19 deaths were associated with BTKi in non-CLL patients. Conclusion(s): We demonstrate a favourable real-world DFS and OS for BTKi-treated CLL patients although a high number of patients still stop BTKi due to Aes. The very high incidence of second malignancies for all BTKi-treated patients and COVID-19 and infection-related deaths for CLL patients is concerning. As CLL is known to associate with high levels of second cancers, it remains unclear whether BTKi use increases this risk further.

Cellular and humoral immune response to SARS-CoV-2 mRNA vaccines in patients treated with either Ibrutinib or Rituximab.

Patients treated with B-cell-targeting therapies like Rituximab or Ibrutinib have decreased serological response to various vaccines. In this study, we tested serological and cellular response to SARS-CoV-2 mRNA vaccines in 16 patients treated with Ibrutinib, 16 treated with maintenance Rituximab, 18 patients with chronic lymphocytic leukaemia (CLL) with watch and wait status and 21 healthy volunteers. In comparison with the healthy volunteers, where serological response was achieved by 100% subjects, patients on B-cell-targeting therapy (Ibrutinib and Rituximab) had their response dramatically impaired. The serological response was achieved in 0% of Rituximab treated, 18% of Ibrutinib treated and 50% of untreated CLL patients. Cell-mediated immunity analysed by the whole blood Interferon-γ Release immune Assay developed in 80% of healthy controls, 62% of Rituximab treated, 75% of Ibrutinib treated and 55% of untreated CLL patients. The probability of cell-mediated immune response development negatively correlates with disease burden mainly in CLL patients. Our study shows that even though the serological response to SARS-CoV-2 vaccine is severely impaired in patients treated with B-cell-targeting therapy, the majority of these patients develop sufficient cell-mediated immunity. The vaccination of these patients therefore might be meaningful in terms of protection against SARS-CoV-2 infection.

Significant reduction in the incidence of non-coronavirus infections in patients with chronic lymphocytic leukemia on ibrutinib and venetoclax treatment during the COVID-19 pandemic: An additional benefit of lockdown.

Effective treatment and prevention of infections challenge management of patients with chronic lymphicytic leukemia (CLL). The COVID-19 pandemic resulted in the reduction of outpatient hospital visits as a part of non-pharmaceutical interventions that could affect the incidence of infectious complications. Study enrolled patients with CLL receiving ibrutinib or/and venetoclax who were observed at the Moscow City Centre of Hematology from 01 April 2017 to 31 March 2021. We found a reduction in the incidence of infectious episodes after the implementation of the lockdown in Moscow in 01 April 2020, when compared to data on the year prior to the lockdown (p < 0.0001), as well as when compared to the predictive model (p = 0.02), and based on individual infection profiles using cumulative sums (p < 0.0001). Bacterial infections had 4.44-fold decrease, bacterial in combination with undefined infections had 4.89-fold decrease, viral infections had unsignificant changes. The decrease in the number of outpatient visits coincides with the time of the lockdown could be a likely factor, explaining a decline in the incidence of infection. Patients were clustered according incidence and severity of infectious episodes for subgroup mortality assessment. No differences in overall survival due to COVID-19 were observed. Typical respiratory infections, bacterial and undefined, the transmission of which may be affected by patient-to-patient contact in the settings of out-patient health care visits were decreased, possibly due to SARS-CoV-2 restrictive measures. A positive correlation between outpatient visits and the incidence of bronchial and upper respiratory tract infection points at the role of hospital-acquired infection and attests to the necessity of reorganizing care for all patients with CLL.

A Case of Fever and Polymorphous Rash in a Patient with Recent Sars-Cov-2 Infection

Introduction. Multisystem inflammatory syndrome in adults (MIS-A) is a rare but potentially life-threatening sequel of SARS-CoV-2 infection, requiring early recognition and treatment. Nevertheless, it is often hard to distinguish MIS-A from other COVID-19-related hyperinflammatory complications. Case presentation. A 74-year-old male presented to the emergency department with persistent fever, diarrhea, altered consciousness, polymorphous rash with oral lesions and erythema of the palms and soles, with progressive exfoliation. The patient had been hospitalized for COVID-19 four weeks before and was suffering from chronic lymphocytic leukemia, diabetes and hypertension. During his recent hospital stay he received multiple courses of antibiotics and was discharged home with instructions to add sitagliptin and re-initiate therapy with ibrutinib. Upon re-admission, polymerase chain reaction test for SARS-CoV-2 was still positive and inflammatory markers were markedly elevated. Although MIS-A could not be excluded, a presumptive diagnosis of Stevens-Johnson Syndrome (SJS) was made, and the patient was treated empirically with intravenous immunoglobulin and high-dose methylprednisolone. SJS is usually considered an adverse drug reaction that affects the skin and mucous membranes. In this patient, MIS-A was also initially included in the differential diagnosis due to previous COVID-19, despite the patient's advanced age and lack of cardiac involvement or conjunctivitis. The patient only partially fulfilled current diagnostic criteria for MIS-A. Conclusions. SJS results from a dysregulated immune response and can have a similar presentation to MIS-A. A better characterization of both conditions is required particularly in older adults with comorbidities, to facilitate timely diagnosis and management and to reduce mortality.Copyright © ENS Editions. Tous droits reserves pour tous pays.

Platelet caspase-1 and Bruton tyrosine kinase activation in patients with COVID-19 is associated with disease severity and reversed in vitro by ibrutinib.

Background: Severity of coronavirus disease 2019 (COVID-19) is often associated with thrombotic complications and cytokine storm leading to intensive are unit (ICU) admission. Platelets are known to be responsible for abnormal hemostasis parameters (thrombocytopenia, raised D-dimers, and prolonged prothrombin time) in other viral infections through the activation of the nucleotide-binding domain leucine repeat rich containing protein 3 inflammasome induced by signaling pathways driven by Bruton tyrosine kinase (BTK) and leading to caspase-1 activation. Objectives: We hypothesized that caspase-1 activation and the phosphorylation of BTK could be associated with the severity of the disease and that ibrutinib, a BTK inhibitor, could inhibit platelet activation. Methods and Results: We studied caspase-1 activation by flow cytometry and the phosphorylation of BTK by Western blot in a cohort of 51 Afro-Carribean patients with COVID-19 disease (19 not treated in ICU and 32 treated in ICU). Patients with a platelet count of 286.7 × 109/L (69-642 × 109/L) were treated by steroids and heparin preventive anticoagulation. Caspase-1 and BTK activation were associated with the severity of the disease and with the procoagulant state of the patients. Furthermore, we showed in vitro that the plasma of ICU patients with COVID-19 was able to increase CD62P expression and caspase-1 activity of healthy platelets and that ibrutinib could prevent it. Conclusions: Our results show that caspase-1 and BTK activation are related to disease severity and suggest the therapeutic hope raised by ibrutinib in the treatment of COVID-19 by reducing the procoagulant state of the patients.

Immunogenicity of a third dose of the BNT162b2 COVID-19 vaccine in patients with CLL: effects on treatment selection.

Patients with chronic lymphocytic leukemia (CLL) show suboptimal responses to the vaccines against SARS-CoV-2; it has been shown though that a booster dose of the BNT162b2 vaccine may lead to a significant increase in the seroconversion rates of immunocompromised patients. We conducted a prospective, non-interventional study to evaluate the immunogenicity of a third dose of the BNT162b2 vaccine in adult patients with CLL. Sera were tested before the first, after the second, and before and after the third dose for anti-SARS-CoV-2 receptor binding domain (RBD) spike protein IgG (anti-RBD). Thirty-nine patients with CLL were included in the study. The seroconversion rate increased from 28.2% before the third dose to 64.1% after the third dose and was higher in treatment-naïve patients (72.7% versus 47.1% in actively treated patients, p = 0.042). All but one patient achieving a seroconversion after the second dose retained after the third, while eight patients not achieving a seroconversion after the second dose (38.1%), did so after the third. Moreover, patients actively treated with venetoclax had a higher seroconversion rate than those treated with ibrutinib (87.5% versus 14.3%, p = 0.001). This study confirms the beneficial effect of a third dose of the BNT162b2 vaccine on the seroconversion rate in patients with CLL. Our results also strongly suggest that the use of venetoclax is correlated with higher immunogenicity/seroconversion rates than that of ibrutinib, a finding that has been reported by another study. A treatment strategy change during the pandemic favoring the use of venetoclax may be suggested based on our results, although these results should be validated in larger studies.

HEMORRHAGIC PLEURAL EFFUSION IN A PATIENT WITH CHRONIC LYMPHOCYTIC LEUKEMIA ON IBRUTINIB THERAPY

SESSION TITLE: Problems in the Pleura Case Posters 1 SESSION TYPE: Case Report Posters PRESENTED ON: 10/17/2022 12:15 pm - 01:15 pm INTRODUCTION: Ibrutinib is an irreversible inhibitor of Bruton's tyrosine kinase (Btk), approved for treatment of a variety of B-cell malignancies, including chronic lymphocytic leukemia (CLL). There is an association of increased risk of bleeding with ibrutinib due to platelet dysfunction caused by the medication. Bleeding is usually non-life threating such as subcutaneous or mucosal bleeding, epistaxis, and ecchymosis. But major bleeding has been reported such as intracranial hemorrhage and gastrointestinal hemorrhage. Thoracic complications from ibrutinib are rare. Below is a case report discussing a hemorrhagic pleural effusion thought to be caused by Ibrutinib. CASE PRESENTATION: Patient is a 78-year-old male initially diagnosed with CLL on flow cytometry showing a low-grade B cell lymphoproliferative process. Patient was monitored by Hematology and when kappa light chain numbers began to rise, a bone marrow biopsy was performed showing 90% infiltration of the marrow with lymphoid cells. Patient was started on Ibrutinib therapy and responded well to treatment. A year after starting therapy, patient presented to the emergency room with increased shortness of breath and fatigue. Patient was found to be COVID-19 positive and chest x-ray showed a large right sided pleural effusion. Thoracentesis was performed draining 1650cc of bloody fluid. Fluid studies revealed a lymphocytic effusion with RBC count 1,185375, WBC of 1751. Cultures and cytology were negative. On further history, patient was without recent trauma or surgery, CTA chest was negative for pulmonary embolism. QuantiFERON Gold test was negative, indicating low likelihood of tuberculosis. Patient was not on any antiplatelet or systemic anticoagulation medications. Ibrutinib therapy was held during hospitalization and pleural effusion did not reaccumulate. Patient passed away during hospital stay secondary to respiratory failure due to COVID-19. DISCUSSION: Ibrutinib is an orally bioavailable bruton tyrosine kinase inhibitor (BTKi) and forms an irreversible covalent bound to BTK at the Cysteine-481 residue. Ibrutinib predisposes to bleeding by inhibiting BTK and Tec, which play a role in the inhibitory signaling pathway of platelet collagen receptors such as glycoprotein VI (GP VI) and C-type lectin-like receptor 2 (CLEC-2). Our patient had no other risk factors for developing a hemorrhagic effusion. CLL itself can cause malignant effusions, one study found the incidence of malignant effusions among patients with CLL to be 9%, but the effusion was noted to be serous or serosanguinous and there was pleural involvement in all patients which was not the case in our patient. CONCLUSIONS: There is currently a minimal amount of data to guide clinicians regarding the use of ibrutinib in patients at high risk of bleeding or on anticoagulant or antiplatelet therapy. It is important to realize bleeding complications related to ibrutinib therapy can occur. Reference #1: Shatzel JJ, Olson SR, Tao DL, McCarty OJT, Danilov AV, DeLoughery TG. Ibrutinib-associated bleeding: pathogenesis, management and risk reduction strategies. J Thromb Haemost. 2017;15(5):835-847. doi:10.1111/jth.13651 Reference #2: Burger JA, Tedeschi A, Barr PM, et al. Ibrutinib as Initial Therapy for Patients with Chronic Lymphocytic Leukemia. N Engl J Med. 2015;373(25):2425-2437. doi:10.1056/NEJMoa1509388 Reference #3: Paydas S. Management of adverse effects/toxicity of ibrutinib. Crit Rev Oncol Hematol. 2019;136:56-63. doi:10.1016/j.critrevonc.2019.02.001 DISCLOSURES: No relevant relationships by fatima ali No relevant relationships by Joan Wiley

IMPORTANCE OF HIGH CLINICAL SUSPICION FOR COVID-19-ASSOCIATED PULMONARY ASPERGILLOSIS IN PATIENTS WITH EQUIVOCAL BIOMARKERS

SESSION TITLE: Pathologies of the Post-COVID-19 World SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 10:15 am - 11:10 am INTRODUCTION: Pulmonary aspergillosis is a recognized complication of COVID-19. Options for diagnostic evaluation in patients with suspected pulmonary aspergillosis include serum galactomannan, beta-D-glucan, Aspergillus PCR, fungal cultures and tissue biopsy. Diagnosis is challenging due to the risks and logistical barriers associated with procedural/surgical tissue biopsy and the variable reliability of serum biomarkers. We present a case of a 76-year-old male who developed invasive pulmonary aspergillosis after a COVID-19 respiratory infection. CASE PRESENTATION: 76-year-old male with a past medical history that includes emphysematous COPD, history of chronic lymphocytic leukemia in remission, on ibrutinib, who contracted SARS-CoV-2 resulting in hypoxemic respiratory failure and requiring hospital admission and was treated with dexamethasone and remdesivir. He was discharged home and due to his worsening respiratory condition, he was readmitted to the hospital next month. Ct chest performed revealed pulmonary embolism and diffuse multifocal opacification with interspersed scattered dense opacities and nodules with cavitary lesions in the right upper lobe. A bronchoscopy was performed and the Aspergillus antibody test, beta D glucan and galactomannan antigens resulted as negative. Due to this, voriconzaole was discontinued. Subsequently CT-guided lung biopsy demonstrated Aspergillus. Eventually, fungal cultures from BAL began growing fungus. DISCUSSION: Our patient initially presented with a Covid infection in January 2022 he was initially treated with remdesivir, 14 days of baricitinib and 10 days of Decadron followed by a steroid taper (due to his underlying COPD). He did not receive tocilizumab. He was found to have progression of the cavitary lesions during a third admission. We suspect that the main contributing factors for the development of invasive pulmonary aspergillosis are related to interleukin production, distorted architecture from COVID-19 infection and multiple courses of steroids. This case report demonstrates the importance of having a high clinical suspicion for invasive pulmonary aspergillosis in all patients with COVID-19 infection. It also demonstrates that serum biomarkers are not reliable indicators of infection and cannot be used to definitively rule out infection or to exclude treatment with antifungal therapy. It should be noted that positive serum biomarkers in patients with true invasive aspergillosis have a higher mortality rate as compared to those without positive serum biomarkers. This case also underscores the importance of obtaining tissue diagnosis in patients where there is a high suspicion for fungal infection when all other studies are equivocal. CONCLUSIONS: We believe that this case underscores the importance of maintaining a high clinical suspicion for opportunistic and fungal infections in patients with COVID-19, regardless of the serum biomarkers. Reference #1: Arastehfar A, Carvalho A, van de Veerdonk FL, et al. Covid-19 associated Pulmonary Aspergillosis (capa)—from immunology to treatment. Journal of Fungi. 2020;6(2):91. doi:10.3390/jof6020091 Reference #2: Machado M, Valerio M, Álvarez-Uría A, et al. Invasive Pulmonary Aspergillosis in the COVID-19 ERA: An expected new entity. Mycoses. 2020;64(2):132-143. doi:10.1111/myc.13213 Reference #3: Maschmeyer G, Haas A, Cornely OA. Invasive aspergillosis. Drugs. 2007;67(11):1567-1601. doi:10.2165/00003495-200767110-00004 DISCLOSURES: No relevant relationships by Hira Bakhtiar No relevant relationships by Amanda Lindo No relevant relationships by Carlos Merino No relevant relationships by Joanna Moore

Early Therapy Intensification for High-Risk Waldenström Macroglobulinemia

Introduction: Waldenström macroglobulinemia is an incurable disease, despite advances in the use of targeted therapy. Aim: To assess the effectiveness of intensive induction immunochemotherapy and its combination with targeted drugs and subsequent autologous stem cell transplantation (auto-SCT). Materials and Methods: Twenty-one patients were selected. Four and 17 patients were in the medium- and high-risk groups, respectively. Twelve patients (57%) had hyperviscosity syndrome, 21 (100%) had anemia, 4 (19%) had platelets <100, 4 had hemolysis, 4 (19%) had cryoglobulinemia, 13 (62%) had lymphadenopathy and splenomegaly, 12 had B-symptoms, 11 had LDH >250 U/L, 6 had albumin <30 g/L, and 11 had β-2-microglobulin >4 mg/L. The mean PIgM was 45.3 g/L and Hb was 82 g/L. Sixteen patients (76%) had an L265P mutation in MYD 88 and 2 patients had del -17p. Results: The mean age of the patients was 51.4 years (33–66 years), with 8 women. Four patients underwent 4 courses - R-EPOCH\R - BAC, 17 patients had the R -EPOCH\R - BAC + ibrutinib, and 15 patients had auto-SCT. BEAM was received by 6 patients. BEAM + daratumumab was received by 9 patients. The overall response was 100%, partial response was 100%, very good partial response was 71%, and CR was 32%. At a median follow-up of 44 months, 5-year overall survival was 93% and 5-year progression-free survival was 87%. After 28 months of observation, progression was observed in 1 patient. One patient died in CR from Covid-19 pneumonia. In the group of patients who received immunochemotherapy with ibrutinib and subsequent high-dose consolidation under the Dara - BEAM program, there was a trend towards an increase in the frequency of CR compared with the rest of the patients: 59% and 18%, respectively. Conclusions: R-EPOCH\ R-BAC + ibrutinib + high-dose consolidation + auto-SCT led to deep responses in 71% of patients. Primary intensification makes it possible to implement the concept of “stop” therapy, which makes it cost-effective. The use of high-dose consolidation according to the Dara-BEAM program increases the effectiveness of treatment. We are continuing the study, which will increase the reliability of the results.

Ibrutinib Treatment and Its Impact on Circulating Immune Cells in Chronic Lymphocytic Leukemia Patients

Context: Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by immune dysregulation, infections represent a cause of mortality and morbidity in CLL. Ibrutinib is a Bruton's tyrosine kinase inhibitor very effective on CLL, but this treatment is burdened by infective complications, especially within the first months of therapy. The decline of infections could suggest that immune competence may be restored by Ibrutinib directly or by reductions in CLL burden. Objective: This monocentric prospective study evaluates immunophenotypic changes in circulating immune cells in CLL patients treated with Ibrutinib. We collected peripheral blood samples at baseline, 3, and 6 months of therapy;new samples at 12 and 24 will be collected. Materials and Methods: Data of 20 patients treated with Ibrutinib in our Centre since January 2021 were collected. Multiparametric flow cytometry was used to characterize immune cells. Median age at Ibrutinib start was 74 years. Nine patients were treatment-naive, 7 were on second-line. The other 4 have already received at least 2 previous therapy lines. In particular, 11 have received chemoimmunotherapy (CIT). Results: The only correlation between clinical-biological data and impact on baseline cells was found between previous exposure to CIT and CD3+HLA-DR+cells (median 1×109/L vs 6×109/L in chemo-naïve patients, p=0.025). No differences in who have received a chemo-free therapy prior to Ibrutinib or based on the number of previous therapy lines. After 6 months of therapy, we observed statistical differences between baseline for CD19+decrease (31×109/L vs 11<109/L, p=0.04). Another difference was found in the decrease of CD3+CD4+count (1×109/L vs 0.76×109/L, p=0.04). Also, the CD3+ count decreased after 6 months (1.7×109/L vs 1.55×109/L, p=0.04). The last significant difference was in the decrease of NK cells (0.5×109/L vs 0.02×109/L, p=0.04). Infectious complication was observed in 8 patients (40%). Specifically, 4 patients experienced COVID-19, 4 pneumonia and one experienced both and a complicated urinary tract infection. Conclusions: These preliminary data show an early reduction of CD4+T-cell subset, dysfunctional in CLL. NKT cells, that mediate tumor immunosurveillance, at baseline were higher than expected but with Ibrutinib they decreased by 59% in 6 months. Further data are needed, but these suggest an impact of Ibrutinib on the immune system that could help on infections.

Haematological Malignancy Presenting in an Unusual Manner

Chronic lymphocytic leukaemia is a haematological malignancy that occurs due to an increased proliferation of mature B lymphocytes. It is considered to be the most common leukaemia in adults. Hyponatremia is commonly seen in such patients. This case report is about a 75-year-old male, who presented with giddiness, followed by altered sensorium. However, the patient had no motor weakness or sensory loss. Initially, a diagnosis of posterior circulation stroke was made but Magnetic Resonance Imaging (MRI) brain did not show associated signs. The routine investigations showed highly elevated total leukocyte count and hyponatremia. The patient was worked up for malignancy and diagnosed with Chronic lymphocytic leukaemia. Oncology reference was taken and treated with tablet Ibrutinib. On discharge, the patient's mentation improved, and he is on regular follow-up.

IBRUTINIB AND RITUXIMAB AS FIRST LINE THERAPY FOR MANTLE CELL LYMPHOMA: A MULTICENTRE, REAL-WORLD UK STUDY

Background: Ibrutinib (IBR) is an oral covalent Bruton tyrosine kinase inhibitor (BTKi), licensed for treatment of relapsed or refractory mantle cell lymphoma (MCL). Under NHS interim Covid-19 agreements in England, IBR with or without rituximab (R) was approved for the frontline treatment for MCL patients (pts) as a safer alternative to conventional immunochemotherapy. Although recent phase 2 studies have reported high response rates in low-risk patients for this combination in the frontline setting, randomised phase 3 and real-world data are currently lacking. Aims: To describe the real-world response rates (overall response rate (ORR), complete response (CR) rate) and toxicity profile of IBR +/-R in adult patients with previously untreated MCL. Methods: Following institutional approval, adults commencing IBR +/-R for untreated MCL under interim Covid-19 arrangements were prospectively identified by contributing centres. Hospital records were interrogated for demographic, pathology, response, toxicity and survival data. ORR/CR were assessed per local investigator according to the Lugano criteria using CT and/or PET-CT. Results: Data were available for 66 pts (72.7% male, median age 71 years, range 41-89). Baseline demographic and clinical features are summarised in Table 1. 23/66 pts (34.8%) had high-risk disease (defined as presence of TP53 mutation/deletion, blastoid or pleomorphic variant MCL, or Ki67%/MiB-1 ≥30%). IBR starting dose was 560mg in 56/62 pts (90%) and was given with R in 22/64 pts (34%). At a median follow up of 8.7 months (m) (range 0-18.6), pts had received a median of 7 cycles of IBR. 19/60 pts (32%) required a dose reduction or delay in IBR treatment. New atrial fibrillation and grade ≥3 any-cause toxicity occurred in 3/59 pts (5.8%) and 8/57 (14.0%) respectively. For the whole population and high-risk pts only, ORR was 74.4% and 64.7% respectively (p=0.2379), with a median time to response of 3.8m, coinciding with the first response assessment scan. Seven pts (16.7%), of whom 2 had highrisk disease, attained CR at a median of 6.0m. ORR for pts receiving vs not receiving R were 84.2% and 66.7% respectively (p=0.1904). IBR was discontinued in 20/61 pts (32.8%) at a median time to discontinuation of 4.1m, due to progressive disease (PD, 19.7%), toxicity (4.9%), death (3.3%;1 pt each of Covid-19 and E. coli infection), pt choice (3.3%) and other unspecified reasons (1.6%). 15/66 pts (22.7%) overall and 7/23 (30.4%) with high-risk disease progressed on IBR at a median time to PD of 4.0m. No pts underwent autologous stem cell transplantation consolidation during the study period. 12/57 pts (21.1%) received second line treatment (R-chemotherapy n=7, Nordic MCL protocol n=2, VR-CAP n=2, pirtobrutinib n=1). Response to second line treatment was CR in 4/11 pts, PD in 7/11. Of the 2 Nordic-treated patients, 1 had CR after cycle 2 and 1 PD. Fourteen pts (21.2%) died during the follow up period, due to MCL (n=11), Covid-19 (n=2) and congestive cardiac failure (n=1). Overall survival was lower for patients with high-risk disease (HR 0.55, p=0.038). Image: Summary/Conclusion: In this real-world UK cohort of pts receiving first-line IBR +/-R for MCL, including older and high-risk pts, we report high ORR rates in a similar range to the phase II Geltamo IMCL-2015 study of combination IBR-R in an exclusively low-risk population. Documented CR rates were lower, possibly reflecting a low usage of rituximab in the Covid-19 pandemic as well as CT assessment of response. Treatment was generally well tolerated, with low rates of toxicityrelated treatment discontinuation. The study is ongoing.

A PHASE 1 STUDY OF PARSACLISIB IN COMBINATION WITH RITUXIMAB, BENDAMUSTINE + RITUXIMAB, OR IBRUTINIB IN PATIENTS WITH PREVIOUSLY TREATED B-CELL LYMPHOMA (CITADEL-112): PRELIMINARY SAFETY RESULTS

Background: Rituximab-based chemoimmunotherapy regimens are backbone treatment (Tmt) for both indolent (follicular [FL], marginal zone [MZL]) and aggressive (diffuse large B-cell [DLBCL], mantle cell [MCL]) B-cell lymphomas. Standard of care (SoC) for relapsed or refractory (R/R) disease includes anti-CD20 in combination with chemotherapy and targeted therapies, such as Bruton's tyrosine kinase inhibitors (eg, ibrutinib) and phosphoinositide 3-kinase (PI3K) inhibitors. Parsaclisib is a potent and highly selective next generation PI3Kδ inhibitor that is currently being investigated in hematological malignancies. Aims: CITADEL-112 (NCT03424122) is an open-label phase 1 study evaluating the safety and tolerability of adding parsaclisib to investigator choice SoC Tmt rituximab (RIT), RIT + bendamustine (BEN), or ibrutinib (IBR) in patients (pts) with R/R B-cell lymphoma. Methods: Enrolled pts were ≥18 years and had histologically confirmed DLBCL, FL, MCL, or MZL, ECOG PS 0-2, were R/R to ≥1 (≥2 for FL) prior systemic therapy, and ineligible for stem cell transplant. Pts received parsaclisib 20 mg orally once daily (QD) for 8 weeks then 20 mg once weekly (QW) in combination with either: RIT 375 mg/m2 IV QW for 4 doses in cycle 1 (± cycle 2) (Tmt A);RIT 375 mg/m2 IV on day 1 + BEN 90 mg/m2 on day 1 and day 2 of each 28-day cycle for ≤6 cycles (Tmt B);or IBR 560 mg QD (Tmt C). Pts received treatment until disease progression, unacceptable toxicity, or withdrawal. Results: At data cutoff (May 14, 2021), 50 pts were treated (16 pts each in Tmt A and C, 18 pts in Tmt B) and 13 pts were ongoing treatment (3 pts in Tmt A, 8 pts in Tmt B, 2 pts in Tmt C). Most pts had received ≥2 prior systemic treatments (81.3%, 61.1%, and 68.8% in Tmt A [range 1-4], B [range 1-4], and C [range 1-7], respectively). The most common reasons for discontinuation were progressive disease (56.3%, 38.9%, and 50.0%) and adverse events (AEs) (12.5%, 11.1%, and 6.3% in Tmt A, B, and C, respectively). One pt in Tmt B experienced a dose-limiting toxicity of grade 4 neutropenia for >14 days. All pts experienced at least 1 treatment-emergent AE (TEAE);in Tmt A, 75.0% had grade ≥3 and 37.5% had serious TEAEs;Tmt B, 83.3% had grade ≥3 and 27.8% had serious TEAEs;and Tmt C, 62.5% had grade ≥3 and 43.8% had serious TEAEs. Common any-grade TEAEs (≥30%) included neutropenia (62.5%), diarrhea (37.5%), and anemia (31.3%) in Tmt A;neutropenia (50.0%), abdominal pain, asthenia, diarrhea, and nausea (each 33.3%) in Tmt B;neutropenia (50.0%) and increased ALT and increased AST (each 37.5%) in Tmt C. Most common grade ≥3 TEAEs (≥15%) were neutropenia (50.0%) and diarrhea (18.8%) in Tmt A, and neutropenia (38.9% and 25.0%) in Tmt B and Tmt C, respectively. Serious TEAEs occurring in >1 pt were COVID-19, diarrhea, and pneumonia (n = 2 each) in Tmt A, and atrial fibrillation (n = 2) in Tmt C. TEAEs with fatal outcome were reported in 2 pts in Tmt A (COVID-19 and COVID-19 pneumonia [n = 1], interstitial lung disease [n = 1]) and 1 pt in Tmt C (COVID-19, acute kidney injury). Parsaclisib dose interruption or dose reduction due to TEAEs occurred in 75.0% and 18.8% of pts, respectively, in Tmt A;66.7% and 27.8% of pts, respectively, in Tmt B;and 56.3% and 18.8% of pts, respectively, in Tmt C. Summary/Conclusion: Parsaclisib 20 mg QD for 8 weeks followed by 20 mg QW can be safely combined with RIT, RIT + BEN, or IBR in pts with R/R B-cell lymphomas. The tolerability profile of the combination regimens was manageable, with no unexpected safety concerns.

DEPLETION AND RECOVERY OF NORMAL B-CELLS DURING AND AFTER TREATMENT WITH CHEMOIMMUNOTHERAPY, IBRUTINIB OR VENETOCLAX

Background: Infectious complications are a major cause of morbidity and mortality in Chronic Lymphocytic Leukaemia (CLL). Therapeutic approaches that deplete CLL cells also affect normal B-cells. Optimal treatment would result in eradication of CLL cells and recovery of normal immune function. FLAIR (ISRCTN01844152) is a phase III trial for previously untreated CLL comparing ibrutinib plus rituximab (IR) with fludarabine, cyclophosphamide and rituximab (FCR) and subsequently amended to also compare ibrutinib plus venetoclax (I+V) and ibrutinib alone (I) with FCR. Measurable residual disease (MRD) and normal B-cell levels were assessed at multiple timepoints. Aims: To assess the depletion of normal B-cells during treatment and recovery after end of treatment. Methods: Participants aged under 75 years with <20% TP53-deleted cells were initially randomised to FCR or IR and subsequently to FCR, IR, I+V or I with the IR arm closed after randomisation of 771 participants to FCR/IR. FCR was given for 6 cycles, while treatment in the IR, I and I+V arms continued for up to 6 years except in participants attaining <0.01% MRD who continued treatment for the time taken to achieved MRD <0.01% and then stopped if MRD remained <0.01%. Month (M) 24 was earliest permitted stopping point. MRD flow cytometry was performed according to ERIC guidelines (panel: CD19/5/20/43/79/81+ROR1, acquisition of 0.5-2.2 million cells, BD Biosciences Lyric). Additional analysis of normal B-cell subsets was performed in a cohort of >500 patients (panel: CD19 to identify B-cells, CD20/5/79b+ROR1 and CD3 to exclude CLL & contaminating cells, with CD27/ 38/IgD/IgM to characterise normal B-cell subsets using a Coulter Cytoflex LX). Results: Normal B-cells were undetectable during FCR treatment and only rarely detectable until 12 months after last FCR cycle. Circulating normal B-cells were reduced in number or undetectable in participants receiving ibrutinibcontaining regimens with greater depletion in the I+V and IR arms relative to I monotherapy. B-progenitors persist through FCR treatment but were depleted during I, I+R or I+V treatment. Normal B-cell levels at 24 and 36 months after randomisation, with time off-treatment if applicable, are shown in Figure 1. In the ibrutinib-containing arms (IR, I, and I+V), there was a trend towards fewer COVID-associated SAE at any time point for participants with detectable B-cells at 24M (4/181, 2.2%) compared to those with no detectable B-cells (14/344, 4.1%) and COVID-associated SAEs were not observed in FCR-treated participants who had recovered any level of normal B-cells by 24M (0/215). However, the data on COVID infections are limited and there was no apparent association between normal B-cell levels at 24M with the proportion of participants experiencing an infectious SAE overall. Assessment of normal B-cell subsets during ibrutinib-based treatment demonstrated a mix of naïve and memory B-cells. Serological response to COVID infection/vaccination in this cohort is currently being performed. Participants stopping I+V treatment at 24-30 months post-randomisation due to MRD eradication showed rapid recovery of normal naive B-cells within 6-12 months after end of treatment in the vast majority (>95%) of evaluable cases. Summary/Conclusion: Normal circulating B-cells are depleted during treatment with rituximab but can persist at a low level during I, IR or I+V treatment. Most patients in remission after treatment with FCR or I+V show recovery of normal B-cells at 12 months of stopping treatment.

IBRUTINIB PLUS VENETOCLAX IN PATIENTS WITH COMPLEX KARYOTYPE AND CHRONIC LYMPHOCYTIC LEUKEMIA

Background: In the largest study of Baliakas et al. (2019) the presence of at least 5 abnormalities, was associated with dismal clinical outcome, independently of the somatic hypermutation status and TP53 status. The presence of 3 or 4 aberrations is defined as clinically relevant in the absence of TP53. Studies by Kittai (2021) and Al-Sawaf (2020) showed the impact of karyotypic complexity on survival in patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib or venetoclax. The complex karyotype (CK) is a topic that is being intensively researched, both in the aspect of increasing karyotypic complexity stratification and clonal evolution. Optimal therapy for patients with CLL has not yet been developed. The combination therapy of ibrutinib and venetoclax was superior to chlorambucil and obinutuzumab in terms of undetectable minimal residual disease (MRD) responses according to data from the GLOW trial (Tunir, 2021). The importance of achieving a complete response with undetectable MRD as the goal of therapy in CLL was proposed (Montserrat, 2005). Aims: The aim of our study is to evaluate the effectiveness of therapy with ibrutinib and venetoclax in combination for the patients with CLL and CK. Methods: This ambilinear observational study included patients with CLL with high genetic complexity (high-CK), defined as >=5 aberrations or CK (>=3 aberrations) in combination with a 17p deletion (CK+del17p). The first retrospective cohort included patients treated with ibrutinib monotherapy (Imono) to progression or intolerable toxicity since May 2015. The second prospective cohort included patients receiving ibrutinib in combination with venetoclax (IVen) since July 2019. Venetoclax therapy was started at the 3rd month of ibrutinib (from the escalation phase). Combination therapy was continued until a complete response, defined as three consecutive PET-CT-negative and MRD-negative results 3 months apart. If this criterion was not achieved at 24th month of therapy, venetoclax was discontinued and ibrutinib continued indefinitely. Results: Seventy-nine patients are included in the study. Twenty-nine patients in the first cohort and 50 patients in the second cohort. The characteristic is presented in Table. At the current follow-up periods, there were no significant differences in PFS and OS regarding a follow-up period <= 24 months (with the exception of death from COVID-19, since patients were not observed at parallel time intervals). In the group of patients treated with Imono, the majority of patients achieved partial remission or partial remission with lymphocytosis by 12 months. In 21 patients from Iven group, with a median follow-up of 7.4 months, a complete remission was achieved (72.4%);of these, 8 had unmeasurable MRD. Four patients did not complete the escalation period. There was a significant difference in the median MRD response achieved between 3 (log10>10) and 12 (log10<0,1) months in IVen group (p=0,03). In 2 patient from the IVen group progression of the disease was noted. Summary/Conclusion: Combination therapy with ibrutinib and venetoclax is an effective oral regimen for high-risk patients with complex karyotype disorders. PFS in both groups is currently not significantly different, which is obviously due to the short follow-up period. Patients receiving the IVen regimen achieve a significantly better response, which paves the way for allogeneic transplantation in these patients.

SEROLOGIC RESPONSE TO THE SECOND AND THIRD DOSE OF THE SARS-COV-2 VACCINE IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA: RESULTS OF A PROSPECTIVE, CENTRALIZED, MULTICENTER STUDY

Background: Patients with chronic lymphocytic leukemia (CLL) show high infection-related morbidity and mortality due to variable degree of humoral and cellular immune deficiency. High Covid-related mortality and reduced response to the SARS-Cov-2 vaccine have been reported in this patient population. Aims: We carried out a prospective multicenter study to define the rate of CLL patients with an appropriate immune response after the mRNA SARS-CoV2 vaccine (Pfizer-BioNTech;Moderna). Methods: Two-hundred patients with CLL received the first dose of the SARS-CoV-2 vaccine between February and August 2021. Centralized assessment of the anti-SARS-Cov-2 IgG levels (Sero Index, Kantaro Quantitative SARS-CoV-2 IgG Antibody, RUO-R&D System) was performed at the Istituto Superiore di Sanità of Rome, Italy. The median followup of this study is 10.7 months (range 1-12.9). Results: The median age of patients was 70 years, the median IgG level was 635 mg/dl, 61% of patients were IGHV unmutated, and 34% showed TP53 disruption. The majority of patients, 83.5%, were previously treated. Prior treatment included chemoimmunotherapy in 20 (10%) patients, ibrutinib-based therapy in 72 (36%;front-line, 21%;advanced line, 15%), venetoclax-based therapy in 75 (37.5%;front-line, 13.5%;advanced line, 24%). Overall, 135 (77.5%) patients had been previously treated with rituximab, 33 (16.5%) of them within 12 months before vaccination. We assessed the serologic response after the second dose of the SARS-CoV2 vaccine in 195 patients while five were excluded from the analysis (positive test before vaccination, 3 patients;lost to the follow-up, 1;Richter syndrome, 1). Adequate levels of anti-SARS-Cov-2 IgG were detected in 76/195 (39%) patients. Age (<70 vs.≥ 70 years;p <0.0001), CIRS value (<6 vs. ≥6;p=0.005), beta-2 microglobulin (<3.5 vs. ≥ 3.5mg/dl;p=0.04), IgG levels (<550 vs. ≤ 550 mg/dl;p <0.0001), prior treatment (p=0.0001), number of prior treatments (0+1 vs. ≥ 2;p=0.002) and the time between prior rituximab and vaccination (>12 vs. ≤12 month;p=0.001) showed a significant impact on the humoral response. In multivariate analysis only age (OR: 0.92 [95% CI: 0.92-0.97] p=0.0001), IgG levels (OR: 0.28 [95% CI: 0.13-0.58] p<0.001), and the time between prior rituximab and vaccination (OR: 0.10 [95% CI: 0.03-0.37] p=0.001), revealed a significant and independent impact on response. When the analysis was restricted to patients who received targeted therapy, in addition to the younger age (OR: 0.96 [95% CI: 0.92-0.99] p=0.04), higher IgG levels at baseline (OR: 0.31 [95% CI: 0.12-0.79] p=0.014), longer time between the start of ibrutinib or venetoclax-based therapy and vaccination (<18 vs.≥18 months;OR: 0.17 [95% CI: 0.06-0.44], p <0.0001) showed a favorable and independent impact on response. Ninety-three% (182/195) of patients received a third dose of the vaccine. A significant increase in the rate of serologic responses, 51.5% (85/165 evaluated patients, p=0.019), was observed after the booster dose. Moreover, a response was detected in 25% (26/103 evaluated patients) of previously seronegative patients. Summary/Conclusion: In this prospective, multicenter, centralized study, we recorded an effective immune response to the SARS-CoV-2 vaccine in about a third of patients with CLL. Younger age, higher IgG levels, no prior treatment, or stable disease after targeted therapy that suggest preserved immunocompetence were associated with a greater likelihood of achieving an effective immune response. A booster dose of the SARS-CoV-2 vaccine proved beneficial also in previously seronegative patients.

INHIBITION OF PROTEIN KINASE CK2 AND BCL-2: A NOVEL THERAPEUTIC STRATEGY TO ANTAGONIZE MANTLE CELL LYMPHOMA CELL GROWTH

Background: Mantle cell lymphoma (MCL) is a B-cell tumor which often relapses. BCR inhibitors (Ibrutinib, Acalabrutinib) and antiapoptotic BCL2-family members blockers BH3-mimetics (Venetoclax, ABT-199) are effective drugs to fight MCL. However, the disease remains incurable, due to therapy resistance, even to the promising Venetoclax and Ibrutinib combination. Therefore, there is a profound need to explore novel useful therapeutic targets. CK2 is a S/T kinase overexpressed in several solid and blood tumors. We demonstrated that CK2, operating through a 'non-oncogene addiction' mechanism promotes tumor cell survival, and counteracts apoptosis, by activating pro-survival signaling cascades, such as NF-κ B, STAT3 and AKT. CK2 could regulate also BCL2 family members. The CK2 chemical inhibitor CX-4945 (Silmitasertib, Sil) is already under scrutiny in clinical trials in relapsed multiple myeloma, solid tumors and COVID-19. Aims: In this work, we tested the effect of CK2 chemical inhibition or knock down on Venetoclax (Ven)-induced cytotoxicity in MCL pre-clinical models to effectively reduce MCL cell growth and clonal expansion. Methods: CK2 expression and BCR/BCL2 related signaling components were analyzed in MCL cells and control cells by Western blotting. CK2 and BCL2 inhibition was obtained with Sil and Ven, respectively and with CK2 gene silencing through the generation of anti-CK2 shRNA IPTG-inducible MCL cell clones. Survival, apoptosis, mitochondrial membrane depolarization and proliferation were investigated by FACS analysis of AnnexinV/PI and JC-10 staining. The synergic action of Ven and Sil was analyzed by the Chou-Talalay combination index (CI) method. CK2 knock down in vivo was obtained in xenograft NOD-SCID mouse models Results: CK2 inactivation (with Sil or CK2 silencing) determined a reduction in the activating phosphorylation of S529 p65/RelA and S473 and S129 AKT, important survival cascades for MCL. Sil or CK2 silencing caused BCL2 and related MCL1 protein reduction, causing cell death. Importantly, we confirmed these results also in an in vivo xenograft mouse model of CK2 knockdown in MCL. Sil +Ven combination increased MCL cell apoptosis, as judged by the augmented frequency of Annexin V positive cells and expression of cleaved PARP protein, and JC-10 mitochondrial membrane depolarization, with respect to the single treatments. Captivatingly, Sil or CK2 gene silencing led to a substantial reduction of the Ven-induced increase of MCL-1, potentially counteracting a deleterious Ven-induced drawback. Analysis of cell cycle distribution confirmed an increased frequency of apoptotic cells in the sub G1 phase in CK2-silenced cells and a modulation of the other phases of the cell cycle. Remarkably, the calculated CI less than 1 suggested a strong synergic cell-killing effect between Sil and Ven, on all the cell lines tested, including those less sensitive or resistant to Ven Summary/Conclusion: We demonstrated that the simultaneous inhibition/knock down of CK2 and BCL2 synergistically cooperates in inducing apoptosis and cell cycle arrest of MCL malignant B-lymphocytes and has the potential of reducing MCL clonal growth, also counterbalancing mechanism of resistance that may arise with Ven. Therefore, CK2 is a rational therapeutic target for the treatment of MCL to be tested in combination with Ibrutinib or Ven.

TREATING BING-NEEL SYNDROME USING A TAILORED APPROACH: EXPERIENCE OF A SPECIALIST NEUROHAEMATOLOGY CLINIC

Background: Bing-Neel syndrome (BNS) is a rare complication of lymphoplasmacytic lymphoma (LPL) comprising LPL infiltration in the central nervous system (CNS). Clinical and radiological features are diverse;the diagnosis is confirmed by cerebrospinal fluid (CSF) analysis using immunological and molecular techniques. Rarely, a tissue biopsy is required. The pattern of presentation including systemic involvement and CSF features inform treatment strategies, which include CNS-penetrating therapies. Aims: To evaluate the diagnostic characteristics of patients with BNS and their influence on therapy. Methods: Data from patients referred between 2011-2021 for management of BNS to our academic neurohaematology centre were retrospectively reviewed. Those with imaging features alone or where it was not possible to distinguish from high-grade transformation were excluded. Results: Thirty-five patients (22 male, 13 female) were identified. Median age at diagnosis of BNS was 65 years (range 48-85). All patients were symptomatic. In 12 patients (34%) BNS was the de novo presentation of the IgM-related disorder, of which 3 (25%) had no detectable bone marrow (BM) infiltration of LPL at diagnosis. Approximately half (17;49%) had previously received therapy for LPL;median time to BNS diagnosis in these was 49 months (range 3-125). At BNS diagnosis, BM involvement with LPL ranged from 0-95%. More than half (14/26;54%) had <10% infiltrate and almost a fifth (4/26) >60%. All patients had leptomeningeal involvement and 8 (23%) additionally had parenchymal CNS disease. The majority had kappa light-chain predominance: IgMκ (n=26), non-IgMκ (n=5), IgMλ (n=3), one unknown. The BNS diagnosis was made on CSF analysis (n=28;80%), leptomeningeal tissue biopsy (n=3;9%) where CSF was non-informative, or by expert opinion based on supportive clinical, radiological and non-definitive CSF features (n=4;11%). Of those with a diagnosis based on CSF studies, B-cell clonality was confirmed by flow cytometry (27/28;96%), MYD88L265P mutation (18/28;64%) and immunoglobulin gene rearrangement (12/28;43%). In 22 samples with a full dataset, median CSF white cell count was 25/ul (1-233), CSF protein 1.69g/l (0.35-6), CSF IgM 9.49mg/l (1.07-61.5). The majority were treated with intensive regimens (rituximab, methotrexate (MTX), cytarabine (ARA-C) + thiotepa/idarubicin;n=30) due to the presence of CNS disease bulk and clinical need, and less commonly ibrutinib (n=3), bendamustine-rituximab (BR, n=1);one patient had intrathecal therapy (MTX, ARA-C) at the height of the COVID pandemic. Of those who received 2 cycles of intensive chemotherapy, 3 had >4 cycles followed by BCNU/thiotepa autologous stem cell transplant;10 proceeded to 'consolidation' (indefinite) ibrutinib to limit intensive chemotherapy or tackle systemic disease. At a median follow up of 26 months (range 1-121), median survival was not reached;2-year overall survival was 91% (95% CI 74-97). Three patients died during treatment (1 invasive fungal infection post COVID-19 during ibrutinib consolidation post MTX/ARA-C based therapy) and 2 during MTX-ARA-C based therapy;7 patients relapsed or progressed and were treated with ibrutinib: 1 relapsed after ibrutinib use, 1 patient was intolerant of ibrutinib and switched to BR. Image: Summary/Conclusion: Our cohort confirms that BNS may present with leptomeningeal disease and/or parenchymal disease, de novo and without systemic disease. Overall outcomes are excellent with intensive regimens, consolidated with or followed by ibrutinib;however, there are treatment-related toxicities emphasising the need for a tailored approach.